默认情况下，.NET生成的RSA密钥对可以用XML或字节流来保存，而JAVA中生成的RSA密钥对只能用字节流来保存。而它们的字节流格式不同，就导致Java中生成的RSA密钥对不能在.NET中使用，而.NET中生成的密钥对又不能在Java中使用。而.NET的XML保存方法我觉得比较有通用性，于是就以.NET中RSA密钥保存的XML格式作为兼容格式，这样它们就可以通用了。下面是Java代码：
PS:在Chrome上用博客园的编辑器设置不了代码折叠，保存后折叠的代码就打不开了。。。
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文件：StringHelper.java
字符串操作辅助类
文件：Base64Helper.java
Base64字符串和字节流互转的辅助类
文件：RsaHelper.java
代码中主要方法说明：
KeyPair generateRSAKeyPair();//生成密钥对
String encodePublicKeyToXml(PublicKey key);//将公钥转换为XML字符串
PublicKey decodePublicKeyFromXml(String xml);//从XML字符串得到公钥
String encodePrivateKeyToXml(PrivateKey key);//将私钥转换为XML字符串
PrivateKey decodePrivateKeyFromXml(String xml);//从XML字符串得到私钥
========================================================
StringHelper.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package com.scbeta.helpers; /**
*
* @author aaa
*/
public class StringHelper { //数组中是否包括某字符串
public static boolean arrayContainsString(String[] array, String key) {
for (String tmpString : array) {
if (tmpString.equals(key)) {
return true;
}
}
return false;
} public static String GetLeftString(String source, String strTail) {
return GetLeftString(source, strTail, false);
} public static String GetLeftString(String source, String strTail, boolean KeepHeadAndTail) {
return GetMiddleString(source, "", strTail, KeepHeadAndTail);
} public static String GetRightString(String source, String strHead) {
return GetRightString(source, strHead, false);
} public static String GetRightString(String source, String strHead, boolean KeepHeadAndTail) {
return GetMiddleString(source, strHead, "", KeepHeadAndTail);
} public static String GetMiddleString(String source, String strHead, String strTail) {
return GetMiddleString(source, strHead, strTail, false);
} public static String GetMiddleString(String source, String strHead, String strTail, boolean KeepHeadAndTail) {
try {
int indexHead, indexTail; if (strHead == null || strHead.isEmpty()) {
indexHead = 0;
} else {
indexHead = source.indexOf(strHead);
} if (strTail == null || strTail.isEmpty()) {
indexTail = source.length();
} else {
indexTail = source.indexOf(strTail, indexHead + strHead.length());
}
if (indexTail < 0) {
indexTail = source.length();
} String rtnStr = "";
if ((indexHead >= 0) && (indexTail >= 0)) {
if (KeepHeadAndTail) {
rtnStr = source.substring(indexHead, indexTail + strTail.length());
} else {
rtnStr = source.substring(indexHead + strHead.length(), indexTail);
}
}
return rtnStr;
} catch (Exception ex) {
return "";
}
}
}
Base64Helper.java:
package com.scbeta.helpers;
import java.io.IOException;
public class Base64Helper {
public static String encode(byte[] byteArray) {
sun.misc.BASE64Encoder base64Encoder = new sun.misc.BASE64Encoder();
return base64Encoder.encode(byteArray);
}
public static byte[] decode(String base64EncodedString) {
sun.misc.BASE64Decoder base64Decoder = new sun.misc.BASE64Decoder();
try {
return base64Decoder.decodeBuffer(base64EncodedString);
} catch (IOException e) {
return null;
}
}
}
RsaHelper.java:
//===================
//作者：aaaSoft
//日期：2011年11月30日
//博客：http://www.cnblogs.com/aaaSoft/
//Email：scbeta@qq.com
//说明：原创文章，转载请注明出处并保留作者信息
//=================== package com.scbeta.helpers.security; import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateCrtKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.RSAPrivateCrtKeySpec;
import java.security.spec.RSAPublicKeySpec; import javax.crypto.Cipher; import com.scbeta.helpers.Base64Helper;
import com.scbeta.helpers.StringHelper; public class RsaHelper {
/**
* 生成RSA密钥对(默认密钥长度为1024)
*
* @return
*/
public static KeyPair generateRSAKeyPair() {
return generateRSAKeyPair(1024);
} /**
* 生成RSA密钥对
*
* @param keyLength
* 密钥长度，范围：512～2048
* @return
*/
public static KeyPair generateRSAKeyPair(int keyLength) {
try {
KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
kpg.initialize(keyLength);
return kpg.genKeyPair();
} catch (NoSuchAlgorithmException e) {
return null;
}
} public static String encodePublicKeyToXml(PublicKey key) {
if (!RSAPublicKey.class.isInstance(key)) {
return null;
}
RSAPublicKey pubKey = (RSAPublicKey) key;
StringBuilder sb = new StringBuilder(); sb.append("<RSAKeyValue>");
sb.append("<Modulus>")
.append(Base64Helper.encode(pubKey.getModulus().toByteArray()))
.append("</Modulus>");
sb.append("<Exponent>")
.append(Base64Helper.encode(pubKey.getPublicExponent()
.toByteArray())).append("</Exponent>");
sb.append("</RSAKeyValue>");
return sb.toString();
} public static PublicKey decodePublicKeyFromXml(String xml) {
xml = xml.replaceAll("\r", "").replaceAll("\n", "");
BigInteger modulus = new BigInteger(1, Base64Helper.decode(StringHelper
.GetMiddleString(xml, "<Modulus>", "</Modulus>")));
BigInteger publicExponent = new BigInteger(1,
Base64Helper.decode(StringHelper.GetMiddleString(xml,
"<Exponent>", "</Exponent>"))); RSAPublicKeySpec rsaPubKey = new RSAPublicKeySpec(modulus,
publicExponent); KeyFactory keyf;
try {
keyf = KeyFactory.getInstance("RSA");
return keyf.generatePublic(rsaPubKey);
} catch (Exception e) {
return null;
}
} public static PrivateKey decodePrivateKeyFromXml(String xml) {
xml = xml.replaceAll("\r", "").replaceAll("\n", "");
BigInteger modulus = new BigInteger(1, Base64Helper.decode(StringHelper
.GetMiddleString(xml, "<Modulus>", "</Modulus>")));
BigInteger publicExponent = new BigInteger(1,
Base64Helper.decode(StringHelper.GetMiddleString(xml,
"<Exponent>", "</Exponent>")));
BigInteger privateExponent = new BigInteger(1,
Base64Helper.decode(StringHelper.GetMiddleString(xml, "<D>",
"</D>")));
BigInteger primeP = new BigInteger(1, Base64Helper.decode(StringHelper
.GetMiddleString(xml, "<P>", "</P>")));
BigInteger primeQ = new BigInteger(1, Base64Helper.decode(StringHelper
.GetMiddleString(xml, "<Q>", "</Q>")));
BigInteger primeExponentP = new BigInteger(1,
Base64Helper.decode(StringHelper.GetMiddleString(xml, "<DP>",
"</DP>")));
BigInteger primeExponentQ = new BigInteger(1,
Base64Helper.decode(StringHelper.GetMiddleString(xml, "<DQ>",
"</DQ>")));
BigInteger crtCoefficient = new BigInteger(1,
Base64Helper.decode(StringHelper.GetMiddleString(xml,
"<InverseQ>", "</InverseQ>"))); RSAPrivateCrtKeySpec rsaPriKey = new RSAPrivateCrtKeySpec(modulus,
publicExponent, privateExponent, primeP, primeQ,
primeExponentP, primeExponentQ, crtCoefficient); KeyFactory keyf;
try {
keyf = KeyFactory.getInstance("RSA");
return keyf.generatePrivate(rsaPriKey);
} catch (Exception e) {
return null;
}
} public static String encodePrivateKeyToXml(PrivateKey key) {
if (!RSAPrivateCrtKey.class.isInstance(key)) {
return null;
}
RSAPrivateCrtKey priKey = (RSAPrivateCrtKey) key;
StringBuilder sb = new StringBuilder(); sb.append("<RSAKeyValue>");
sb.append("<Modulus>")
.append(Base64Helper.encode(priKey.getModulus().toByteArray()))
.append("</Modulus>");
sb.append("<Exponent>")
.append(Base64Helper.encode(priKey.getPublicExponent()
.toByteArray())).append("</Exponent>");
sb.append("<P>")
.append(Base64Helper.encode(priKey.getPrimeP().toByteArray()))
.append("</P>");
sb.append("<Q>")
.append(Base64Helper.encode(priKey.getPrimeQ().toByteArray()))
.append("</Q>");
sb.append("<DP>")
.append(Base64Helper.encode(priKey.getPrimeExponentP()
.toByteArray())).append("</DP>");
sb.append("<DQ>")
.append(Base64Helper.encode(priKey.getPrimeExponentQ()
.toByteArray())).append("</DQ>");
sb.append("<InverseQ>")
.append(Base64Helper.encode(priKey.getCrtCoefficient()
.toByteArray())).append("</InverseQ>");
sb.append("<D>")
.append(Base64Helper.encode(priKey.getPrivateExponent()
.toByteArray())).append("</D>");
sb.append("</RSAKeyValue>");
return sb.toString();
} // 用公钥加密
public static byte[] encryptData(byte[] data, PublicKey pubKey) {
try {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, pubKey);
return cipher.doFinal(data);
} catch (Exception e) {
return null;
}
} // 用私钥解密
public static byte[] decryptData(byte[] encryptedData, PrivateKey priKey) {
try {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE, priKey);
return cipher.doFinal(encryptedData);
} catch (Exception e) {
return null;
}
} /**
* 根据指定私钥对数据进行签名(默认签名算法为"SHA1withRSA")
*
* @param data
* 要签名的数据
* @param priKey
* 私钥
* @return
*/
public static byte[] signData(byte[] data, PrivateKey priKey) {
return signData(data, priKey, "SHA1withRSA");
} /**
* 根据指定私钥和算法对数据进行签名
*
* @param data
* 要签名的数据
* @param priKey
* 私钥
* @param algorithm
* 签名算法
* @return
*/
public static byte[] signData(byte[] data, PrivateKey priKey,
String algorithm) {
try {
Signature signature = Signature.getInstance(algorithm);
signature.initSign(priKey);
signature.update(data);
return signature.sign();
} catch (Exception ex) {
return null;
}
} /**
* 用指定的公钥进行签名验证(默认签名算法为"SHA1withRSA")
*
* @param data
* 数据
* @param sign
* 签名结果
* @param pubKey
* 公钥
* @return
*/
public static boolean verifySign(byte[] data, byte[] sign, PublicKey pubKey) {
return verifySign(data, sign, pubKey, "SHA1withRSA");
} /**
*
* @param data 数据
* @param sign 签名结果
* @param pubKey 公钥
* @param algorithm 签名算法
* @return
*/
public static boolean verifySign(byte[] data, byte[] sign,
PublicKey pubKey, String algorithm) {
try {
Signature signature = Signature.getInstance(algorithm);
signature.initVerify(pubKey);
signature.update(data);
return signature.verify(sign);
} catch (Exception ex) {
return false;
}
}
}
==============================
下面是测试代码：
public static void main(String[] args) {
KeyPair kp = RsaHelper.generateRSAKeyPair();
PublicKey pubKey = kp.getPublic();
PrivateKey priKey = kp.getPrivate();
String pubKeyXml = RsaHelper.encodePublicKeyToXml(pubKey);
String priKeyXml = RsaHelper.encodePrivateKeyToXml(priKey);
System.out.println("====公钥====");
System.out.println(pubKeyXml);
System.out.println("====私钥====");
System.out.println(priKeyXml);
PublicKey pubKey2 = RsaHelper.decodePublicKeyFromXml(pubKeyXml);
PrivateKey priKey2 = RsaHelper.decodePrivateKeyFromXml(priKeyXml);
System.out.println("====公钥对比====");
System.out.println(pubKey.toString());
System.out.println("------");
System.out.println(pubKey2.toString());
System.out.println("====私钥对比====");
System.out.println(priKey.toString());
System.out.println("------");
System.out.println(priKey2.toString());
try {
String pubKeyXml3 = "<RSAKeyValue><Modulus>rHESyuI3ny4MLsqDBalW9ySaodCL0e6Bsrl01Q5G1qm2wjUoGULazZSNqZY+JQNjU92tW3Snk5RPIkv+wDj+uOT9LTUjQImltHnzqMvbt06GipVXDOyBLTa7G/zRIe/CrjyJ+XEYX2xIhpe5ayowl3HHUpZ71jRNioyxaVVZ8S0=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";
String priKeyXml3 = "<RSAKeyValue><Modulus>rHESyuI3ny4MLsqDBalW9ySaodCL0e6Bsrl01Q5G1qm2wjUoGULazZSNqZY+JQNjU92tW3Snk5RPIkv+wDj+uOT9LTUjQImltHnzqMvbt06GipVXDOyBLTa7G/zRIe/CrjyJ+XEYX2xIhpe5ayowl3HHUpZ71jRNioyxaVVZ8S0=</Modulus><Exponent>AQAB</Exponent><P>5a7uM+IeY8QMVQl0q88ZTqWbB555l7+366cUIClTN8z2ZXzTnWFCNoQzUrG14FouJFYumFZD12Ni5MkJK6gqSw==</P><Q>wDMhwwO4kz82uSG+FlCBr06fYk2COTg0TofmSp/5OrVqgkBIe7FgpTpVGzGLk0mvOLcy6UZftq//W0Saow6nZw==</Q><DP>FbjDgliiMyE5YVlxlUYSyKNU1BWivj09caXte1UtL5vMubBiewHVtz4tdGamIr+kmX8lDPcrl1Uo5yY0HdLbnQ==</DP><DQ>kIjjJsgxkWnEOUyKqjU4kSDK8x3ehDEkBLpmEFBlGCU9R14YJAyr5RUM0zpbABQ1VK1P9+UYLUYE/hmFQIHQmQ==</DQ><InverseQ>pxQDThwSnUZ4EaNaCPl1ovYypdQUZaZ/Sld1+0n8FEjkmRcGP1R9VMuj1ViPZg3rvm2GeP8Xv1SJqJUVueWiGA==</InverseQ><D>DxBNoPWEAF7IZ6n/KhZx52MGMw6BuFQKdm9m+lml7Iik03BLUXGapYzNlzvtr9QM8D2UMEIPhX/WLdvPpEEWVzGnD7XpLXjGwfu1ZkJRcXPEZEZ2subh5ZBqOWCFWKv5WwgGYWuYDLHfrBlBgSFWR8cZuyqkmMsWl4CiadXqGA0=</D></RSAKeyValue>";
System.out.println((new Date()).toLocaleString() + ": 加载公钥中。。。");
PublicKey pubKey3 = RsaHelper.decodePublicKeyFromXml(pubKeyXml3);
System.out.println((new Date()).toLocaleString() + ": 加载私钥中。。。");
PrivateKey priKey3 = RsaHelper.decodePrivateKeyFromXml(priKeyXml3);
String dataStr = "Java与.NET和平共处万岁！";
byte[] dataByteArray = dataStr.getBytes("utf-8");
System.out.println("data的Base64表示："
+ Base64Helper.encode(dataByteArray));
System.out.println((new Date()).toLocaleString() + ": 加密中。。。"); // 加密
byte[] encryptedDataByteArray = RsaHelper.encryptData(
dataByteArray, pubKey3);
System.out.println("encryptedData的Base64表示："
+ Base64Helper.encode(encryptedDataByteArray));
System.out.println((new Date()).toLocaleString() + ": 解密中。。。"); // 解密
// byte[]
byte[] decryptedDataByteArray = RsaHelper.decryptData(
encryptedDataByteArray, priKey3);
System.out.println(new String(decryptedDataByteArray, "utf-8"));// 签名
System.out.println((new Date()).toLocaleString() + ": 签名中。。。");
byte[] signDataByteArray = RsaHelper.signData(dataByteArray,
priKey3);
System.out.println("signData的Base64表示："
+ Base64Helper.encode(signDataByteArray)); // 验签
System.out.println((new Date()).toLocaleString() + ": 验签中。。。");
boolean isMatch = RsaHelper.verifySign(dataByteArray,
signDataByteArray, pubKey3);
System.out.println("验签结果：" + isMatch);
} catch (Exception ex) {
ex.printStackTrace();
}
}
最后，补充一段C#产生密钥对的代码片段如下：
using System.Security.Cryptography;
//密钥位数
int keySize = 1024;
//产生密钥对
RSACryptoServiceProvider rSACryptoServiceProvider = new RSACryptoServiceProvider(keySize);
//得到公钥
String publicKey = rSACryptoServiceProvider.ToXmlString(false);
//得到私钥
String privateKey = rSACryptoServiceProvider.ToXmlString(true);
附上我用C#编写的“RSA密钥对生成器”，点此下载。